CN104433402A - Folding seat - Google Patents

Abstract

The invention provides a folding seat, comprising a seat part, wherein the seat part comprises: a face frame to which a first foot stand is hinged at an upper end thereof so as to be rotatable with respect to the face frame about a hinge position; a movable frame hinged to the face frame so as to be rotatable with respect to the face frame about a hinge position; a second foot rest having an upper end hinged to a free end of the movable frame so as to be rotatable with respect to the movable frame about a hinged position; the two ends of the first pull rod are respectively hinged to the first foot rest and the movable frame, so that the movable frame and the first foot rest rotate in a combined manner under the restraint of the surface frame and the first pull rod; and two ends of the second pull rod are respectively hinged to the face frame and the second foot rest, so that the second foot rest and the face frame rotate in a combined manner under the constraint of the movable frame and the second pull rod. The folding seat with the adjustable backrest angle can be obtained by implementing the invention.

Description

a folding seat

technical field

The invention relates to the field of portable seats, in particular to a foldable seat.

Background technique

With the increasing population density, the living area occupied by human beings is getting bigger and bigger. However, due to limited resources and space, today's home decoration design will increasingly take into account the size of the space occupied by furniture, electrical appliances, etc. and whether their functions are diverse. . Traditional chairs occupy a relatively large volume of space both horizontally and vertically. When a larger open space is needed at home or in the office, such traditional chairs must be completely removed from the space, which is very inconvenient. And this chair does not have the function of adjusting the angle of the backrest. When it is necessary to adjust the backrest of the chair for better rest or when an emergency patient needs to lie flat for transportation, ordinary chairs cannot meet the demand.

Therefore, need a kind of foldable seat with adjustable backrest angle, if necessary, the angle of backrest and surface frame can be adjusted to 180 degrees and used as a stretcher.

Contents of the invention

The object of the present invention is to provide a folding seat with adjustable backrest angle. For this reason, a kind of foldable seat that the present invention provides includes a seat, and it is characterized in that, the seat includes: a surface frame, a first foot frame, and the upper end of the first foot frame is hinged to the surface frame, thereby being able to to rotate relative to the surface frame about the hinge position; the movable frame is hinged to the surface frame so as to be able to rotate relative to the surface frame about the hinge position; the second foot frame, the second foot frame The upper end is hinged to the free end of the movable frame, so that it can rotate relative to the movable frame at the hinged position; the first pull rod, the two ends of which are respectively hinged to the first tripod and the movable frame, so that the movable frame Jointly rotate with the first tripod under the constraints of the surface frame and the first tie rod; the two ends of the second tie rod are respectively hinged to the seat part and the second tripod, so that the second tripod Combined rotation with the surface frame under the constraints of the movable frame and the second tie rod.

As a preferred solution, the first stand includes a first support leg and a second support leg, the upper end of the first support leg is hinged to the first hinge position of the seating part, and the upper end of the second support leg is hinged to the seat. The second hinged position of the seating part; the movable frame includes a first movable rod and a second movable rod, and the hinged end of the first movable rod is hinged to the third hinged position of the seated part; the second movable rod The hinged end of the seat is hinged to the fourth hinged position of the seating part; the line defined by the third hinged position and the fourth hinged position is substantially parallel to the straight line defined by the first hinged position and the second hinged position, A third reinforcing rod is connected between the first movable rod and the second movable rod; the second tripod includes a third supporting leg and a fourth supporting leg, and the upper end of the third supporting leg is hinged to the first movable The fifth hinged position of the rod, the upper end of the fourth support leg is hinged to the sixth hinged position of the second movable rod, the straight line defined by the fifth hinged position and the sixth hinged position is substantially parallel to the A straight line defined by the third hinge position and the fourth hinge position; one end of the first pull rod is hinged to the seventh hinge position of the first movable rod, and the other end is hinged to the eighth hinge position of the first support leg; One end of the second pull rod is hinged to the ninth hinge position of the seating part, and the other end is hinged to the tenth hinge position of the third support leg; the folding seat further includes a third pull rod and a fourth pull rod, the One end of the third pull rod is hinged to the eleventh hinge position of the second movable rod, and the other end is hinged to the twelfth hinge position of the second support leg; one end of the fourth pull rod is hinged to the first hinge position of the seating part The thirteenth hinged position, the other end is hinged to the fourteenth hinged position of the fourth support leg; the third pull rod is basically parallel to the first pull rod and has substantially the same length, and the fourth pull rod is basically parallel to the first pull rod The second pull rods are substantially equal in length.

As a preferred solution, the first stand includes a first support leg, a second support leg and a first reinforcing rod, and the two ends of the first reinforcing rod are respectively fixed to the first support leg and the second support legs, the upper end of the first supporting leg is hinged to the first hinged position of the seat part, and the upper end of the second supporting leg is hinged to the second hinged position of the seated part; the movable frame includes a first movable rod and a second A movable rod, the hinged end of the first movable rod is hinged to the third hinged position of the seat part; the hinged end of the second movable rod is hinged to the fourth hinged position of the seated part; the third hinged position The straight line defined by the fourth hinge position is substantially parallel to the straight line defined by the first hinge position and the second hinge position, and a third reinforcing rod is connected between the first movable rod and the second movable rod; The tripod includes a third support leg, a fourth support leg and a second reinforcing rod, the two ends of the second reinforcing rod are respectively fixed to the third supporting leg and the fourth supporting leg, and the third supporting leg The upper end is hinged to the fifth hinged position of the first movable rod, the upper end of the fourth support leg is hinged to the sixth hinged position of the second movable rod, and the fifth hinged position is connected to the sixth hinged position The defined straight line is substantially parallel to the straight line defined by the third hinged position and the fourth hinged position; one end of the first pull rod is hinged to the seventh hinged position of the first movable rod, and the other end is hinged to the first hinged position. The eighth hinged position of the tripod; one end of the second pull rod is hinged to the ninth hinged position of the seating part, and the other end is hinged to the tenth hinged position of the second tripod.

As a preferred solution, the folding seat further includes a backrest for leaning on, and the bottom of the backrest is hinged to the seating part so that the backrest can rotate relative to the seating part.

As a preferred solution, the folding seat further includes a landing gear for adjusting the angle of the backrest relative to the seating part, the landing gear includes a vertical part, and the vertical part is rotatably connected to the the backrest so that the vertical part can rotate relative to the backrest; the folding seat also includes an adjustment box, the adjustment box is installed on the seat part; the free end of the vertical part of the undercarriage can be The adjustment box is inserted into and fixed or released by the adjustment box, so that the rotation angle of the backrest relative to the seating part can be controlled.

As a preferred solution, the upper cover and the lower bottom of the adjustment box are respectively provided with landing gear through holes for the vertical part of the landing gear to pass through; the vertical part of the landing gear is provided with several notches, so The adjustment box is provided with a chuck for snapping into the notch to fix the position of the undercarriage; the width of the through hole of the undercarriage is slightly larger than the vertical part of the undercarriage, and the through hole of the undercarriage has a Sufficient length to allow the vertical part of the undercarriage to swing due to the rotation of the backrest part.

As a preferred solution, the folding seat further includes a handle, one end of which is inserted into the adjustment box and fixedly connected with the chuck, and the other end protrudes out of the adjustment box.

As a preferred solution, the folding seat further includes a spring assembly for relieving the impact force when the backrest is adjusted in angle, the spring assembly includes a spring shaft and a main spring, and one end of the spring shaft is rotatably connected to the backrest And basically parallel to the vertical part of the landing gear, the other end is a free end and can be inserted into the adjustment box; After the included angle of the backrest part is greater than the preset angle, the two ends of the main spring are respectively compressed by the backrest part and the adjustment box.

As a preferred solution, a baffle protrudes vertically inward/outward from the side of the undercarriage through hole of the upper cover or lower bottom of the adjustment box facing the notch to prevent the notch from Block the upper cover or the lower bottom of the adjustment box.

As a preferred solution, the adjustment box is equipped with a return spring, and one end of the return spring is fixedly connected with the chuck for returning the chuck to a position engaged with the notch.

Implementing the present invention can obtain a folding seat with an adjustable backrest angle. If necessary, the backrest can be adjusted to 180° with the surface frame and can be used as a stretcher.

Description of drawings

Fig. 1 is a schematic structural view of a folding seat provided by the present invention;

Fig. 2 is a structural schematic view of the use state of the seat part of the folding seat shown in Fig. 1;

Fig. 3 is a schematic structural diagram of the half-folded state of the seating part shown in Fig. 2;

Fig. 4 is a schematic structural diagram of the half-folded state of the seating part shown in Fig. 2;

Fig. 5 is a schematic diagram of a fully folded state of the seating part shown in Fig. 2;

Fig. 6 is a structural schematic diagram of the backrest of the folding seat shown in Fig. 1;

Fig. 7 is a structural schematic diagram of the adjustment part of the folding seat shown in Fig. 1 except the adjustment box;

Fig. 8 is a structural schematic diagram of the adjustment box of the folding seat shown in Fig. 1;

Fig. 9 is a schematic diagram of the internal structure of the adjustment box shown in Fig. 8;

Fig. 10 is a schematic diagram of the internal structure on the upper surface of the adjustment box shown in Fig. 8 .

Detailed ways

Referring to FIG. 1 , a foldable seat provided by the present invention mainly includes a seat portion 100 , a backrest portion 200 and an adjustment portion 300 .

Referring to FIGS. 2-4 , the seating part 100 includes a surface frame 110 , a first leg frame 120 , a second leg frame 130 and a movable frame 140 . The first stand 120 includes a first support leg 121 and a second support leg 123 , the upper ends of the first support leg 121 and the second support leg 123 are respectively hinged to the first hinge position and the second hinge position of the seating part 100 . In this embodiment, the first hinged position and the second hinged position are located at the first side 111 of the seating part, but the present invention is not limited to this manner. Preferably, the first hinge position and the second hinge position are respectively located at the two ends of the first side 111 or near the two ends. The first supporting leg 121 and the second supporting leg 123 are fixedly connected by the first reinforcing rod 163, and the first reinforcing rod 163 is substantially perpendicular to the first supporting leg 121 and the second supporting leg 123, so that the first leg is H-shaped Or an H shape with a narrow top and a wide bottom, which can rotate relative to the surface frame 110 as a whole around the straight line defined by the first hinge position and the second hinge position.

In the unfolded state of the folded seat, the second leg 130 is used to support the second side 113 at the bottom of the surface frame 110 . In this embodiment, the first side 111 is opposite to the second side 113 and parallel to each other. The second stand 130 includes a third support leg 125 and a fourth support leg 127 for supporting the ground. Similarly, the third support leg 125 and the fourth support leg 127 are fixedly connected by the second reinforcement rod 165, and the second reinforcement rod 165 is substantially perpendicular to the third support leg 125 and the fourth support leg 127, so that the second tripod 130 is also H-shaped or H-shaped with a narrow top and a wide bottom, and can move relative to the surface frame 110 as a whole.

In the case of a higher tripod, another reinforcing bar parallel to the first reinforcing bar 163 can be added between the first supporting leg 121 and the second supporting leg 123; Another reinforcing bar parallel to the second reinforcing bar 165 is added between the four supporting legs 127 to play the role of structural reinforcement. The movable frame 140 is designed in order to facilitate the folding of the seating part 100, the movable frame 140 is used to connect the second foot frame 130 to the surface frame 110, the movable frame 140 includes a first movable bar 141 and a second movable bar 143, the first movable One end of the rod 141 is hinged to a third hinged position of the seating part 100 , and in this embodiment, the third hinged position is located near the middle of the third side 115 of the seating part 100 . One end of the second movable rod 143 is hinged to the fourth hinged position of the seating part 100 , and in this embodiment, the fourth hinged position is located near the middle of the fourth side 117 of the seating part. In this embodiment, the third side 115 and the fourth side 117 of the surface frame are substantially parallel, and the first movable rod 141 and the second movable rod 143 are substantially parallel. Preferably, a third reinforcing rod 167 is fixedly connected between the first movable rod 141 and the second movable rod 143, and the third reinforcing rod 167 is substantially perpendicular to the first movable rod 141 and the second movable rod 143, so that the third The reinforcing rod 167 , the first movable rod 141 and the second movable rod 143 form an H shape and can rotate relative to the surface frame 110 integrally.

As an optional solution, the reinforcing rod 167 added between the first movable rod 141 and the second movable rod 143 may be one or several. For example, in this embodiment, two reinforcing rods 167 and 168 are added between the first movable rod 141 and the second movable rod 143 . These two reinforcing rods are separated by a certain distance and are basically parallel to each other, forming a ladder shape together with the first movable rod 141 and the second movable rod 143 .

The upper end of the third supporting leg 125 is hinged to the fifth hinged position of the first movable rod 141 , and the lower end is used for landing. The upper end of the fourth supporting leg 127 is hinged to the sixth hinged position of the second movable rod 143 , and the lower end is used for landing. In this way, the second leg frame 130 can rotate relative to the movable frame 140 /surface frame 110 as a whole around the straight line defined by the fifth hinged position and the sixth hinged position. A line defined by the fifth hinge position and the sixth hinge position is substantially parallel to a line defined by the third hinge position and the fourth hinge position.

As mentioned above, because the first leg frame 120 can rotate relative to the surface frame 110, the movable frame 140 can rotate relative to the surface frame 110, and the second leg frame 130 is hinged to the free end of the movable frame 140 and can rotate relative to the movable frame 140. , Therefore, when folding, the second leg frame 130 can approach the first leg frame 120 and finally stick together (Fig. 4). Together.

In order to control and coordinate the relative position relationship and moving process of the first foot frame 120, the second foot frame 130 and the movable frame 140, the folding seat is also provided with several pull bars for connecting the first foot frame 120, the second foot frame 130 and Activity frame 140.

Wherein, one end of the first pull rod 151 is connected to the seventh hinged position 171 of the first movable rod 141 of the movable frame 140 , and the other end is connected to the eighth hinged position 172 of the first supporting leg 121 . In this way, the first movable rod 141, the surface frame 110, the first support leg 121, and the first pull rod 151 are connected into a quadrilateral (see Figure 4), and the relative movement between these four is restricted by the side length of the quadrilateral, for example When the first movable rod 141 of the movable frame 140 rotates relative to the surface frame 110 , the first support leg 121 is urged to rotate relative to the surface frame 110 through the first pull rod 151 .

One end of the second tie rod 153 is hinged to the ninth hinged position 173 of the third side 115 of the surface frame 110 , and the other end is hinged to the tenth hinged position 174 of the third supporting leg 125 . In this way, the first movable rod 141, the surface frame 110, the third support leg 125, and the second pull rod 153 are connected into a quadrilateral, and the relative movement between these four is restricted by the side length of the quadrilateral, for example, the movable frame 140 When the first movable rod 141 rotates relative to the surface frame 110 , the third support leg 121 is urged to rotate relative to the first movable rod 141 through the second pull rod 153 .

As mentioned above, the first leg 120 is H-shaped as a whole, so the second support leg 123 and the first support leg 121 move synchronously. Similarly, the fourth support leg 127 of the second tripod 130 moves synchronously with the third support leg 125, and the second movable rod 143 of the movable frame 140 moves synchronously with the first movable rod 141. Therefore, the above-mentioned first The pull rod 155 can substantially constrain the relative movement of the entire movable frame 140, the entire first leg frame 120 and the surface frame 110; The relative movement of the frame 110.

It should be appreciated that the third tie rod 155 and the fourth tie rod 157 may also be added to strengthen the above-mentioned constraint relationship. In this embodiment, one end of the third pull rod 155 is connected to the eleventh hinged position 175 of the second movable rod 143 , and the other end is connected to the twelfth hinged position 176 of the second supporting leg 123 . The third tie rod 155 is basically parallel to the first tie rod 151 , and has a similar function to that of the first tie rod 151 , which will not be repeated here. One end of the fourth pull rod 157 is hinged to the thirteenth hinged position 177 of the fourth side 117 of the surface frame, and the other end is hinged to the fourteenth hinged position 178 of the fourth supporting leg. The fourth tie rod 157 is basically parallel to the second tie rod 153 , and has a similar function to that of the second tie rod 157 , which will not be repeated here.

The surface frame 110, the first foot frame 120, and the second foot frame 130 form a supporting frame, and the supporting frame formed by the surface frame and the foot frame is respectively restrained by the first pull rod 151 and the second pull rod 153 to fix the seating part.

Referring to FIG. 1 , the adjustment part 300 includes an adjustment box 310 and an undercarriage 320 for adjusting the angle of the backrest. The adjustment box 310 is installed on the outer surface of the second side 113 of the surface frame 110 , one end of the landing gear 320 is hinged to the backrest 200 , and the other end is inserted into the adjustment box 310 . It should be appreciated that the larger the angle formed by the backrest 200 and the surface frame 110 is, the longer the landing gear 320 protrudes into the adjustment box 310 . The adjustment box 310 has a device capable of locking the protruding length of the landing gear 320 , thereby fixing the rotation angle of the backrest 200 relative to the surface frame 110 .

In this embodiment, the adjusting part 300 is further provided with a spring assembly 330 . Preferably, the spring assembly 330 is normally in a compressed state. When the user wants to increase the angle formed by the backrest 200 and the surface frame 110, the rotation direction of the backrest 200 is the same as the direction of gravity, and the spring assembly 330 is further compressed to prevent the backrest 200 from falling down too quickly. When the user narrows the angle formed by the backrest 200 and the surface frame 110, the rotation direction of the backrest 200 is opposite to the direction of its gravity, and is the same as the direction of the elastic force of the spring assembly 330, that is, the spring assembly 330 provides assistance.

Referring to FIG. 1 and FIG. 7 , the landing gear 320 is approximately T-shaped, including a beam 321 , and a pin 323 vertically connected to the beam 321 . The lower end of the pin 323 is provided with several notches 324 . Preferably, the pin 323 is flat. The spring assembly 330 includes a spring post 332 and a main spring 334 sleeved on the spring post 332 . The spring post 332 is also connected vertically to the beam 321 and parallel to the pin 323 . The spring post 332 is mainly to prevent the main spring 334 from bending undesirably. As a solution, the lower edges of the two uppermost notches 324 are inclined downward from the inside to the outside, so that the maximum angle thereof can be automatically reduced.

Referring to FIG. 8 to FIG. 10 , the upper cover of the handle adjustment box 310 has a landing gear through hole 311 a through which the pin 323 of the landing gear 320 passes through, and a through hole 312 a through which the spring column 323 passes through. The width of the through hole 311 a is slightly larger than the width of the pin 323 (the size of the pin in the concave direction of the notch 324 ), and the width of the hole 312 a is slightly larger than the outer diameter of the spring post 332 . The holes 311 a , 311 b have a certain length along the rotation direction of the backrest 200 , so that the landing gear through holes 311 a , 311 b can allow the lower end of the landing gear 320 to swing during the rotation of the backrest 200 . Similarly, the lower bottom of the adjustment box 310 has a landing gear through hole 311b through which the pin 323 of the landing gear 320 passes through, and a through hole 312b through which the spring post 323 passes through.

It should be appreciated that the lower end of the main spring 334 should not pass through the adjustment box 310, so as to relieve the impact force when adjusting the angle of the backrest and ensure the safety of the user. In this embodiment, the lower end of the main spring 334 is placed on the upper cover of the adjustment box 310. The width of the spring shaft hole 312a is smaller than the diameter of the main spring 334 to prevent the main spring 334 from passing through the spring shaft hole 312a. The spring shaft holes 312a, 312b The length is greater than the diameter of the spring shaft 332 so that the spring shaft 332 can swing with the rotation of the backrest part 200 in a small range. Preferably, a reinforcing plate 316 for strengthening the structure is provided on one side or around the hole 312a of the upper cover of the adjustment box 310 .

The upper cover of the adjustment box 310 and/or the undercarriage through-holes 311a, 311b at the bottom face the side of the notch 324 inwards/outwards (the bottom can only be outwards) and vertically stretch out a baffle plate 301, which is used to prevent The notch 324 blocks the upper cover and/or the lower bottom of the adjustment box 310 . Preferably, the baffle 301 is located inside the box.

Referring to FIG. 8 and FIG. 9 , a handle 313 for helping to fix the insertion position of the pin 322 of the landing gear 320 is installed on one side of the adjustment box 310 . One end of the handle 313 inserted into the adjustment box 310 is fixedly connected with a chuck 314, and the chuck 314 is inserted into any notch 324 under the push of the handle 313 for fixing the position of the landing gear. The inner surface of the bottom of the adjustment box 310 is provided with a raised first cylinder 315a, the upper surface of the chuck 314 is provided with a raised second cylinder 315b, and the first cylinder 315a and the second cylinder 315b are connected by a return spring 317 , the return spring 317 applies a force to the chuck 314 in the opposite direction to the pulling handle 313, and this elastic force promotes the chuck 314 to be stably engaged and locked with the current notch of the latch 322, ensuring the stability of the adjustment box. When the backrest 200 needs to be rotated again, the handle 313 is pulled outward by hand to release the locking between the chuck 314 and the latch. The chuck 314 is provided with a long and narrow U-shaped through hole 318 along its moving direction, and the limit screw 319a is installed on the bottom of the adjustment box 310 through the limit nut 319b and passes through the U-shaped through hole 318 to limit the 314 chucks. It can move back and forth in a single direction to ensure the stability of the overall structure of the adjustment part 300, and the screw 319a and the nut 319b are loosely matched. There is also a meson 319C between the nut 319b and the chuck 314. The width of the meson 319C is larger than the width of the U-shaped through hole 318. The function of the meson 319C is to limit the range of the chuck 314 to move up and down.

The folding seat provided by the present invention can adjust the angle of the backrest through the adjustment part 300 during actual use. For example, in the first state, the angle between the backrest 200 and the surface frame 110 is 90°. When the angle needs to be slightly increased, the handle 313 can be pulled outwards, and the chuck 314 is separated from the landing gear. Then the backrest 200 is rotated backwards. The backrest 200 can rotate freely due to the hinged connection with the surface frame 110. The main spring 334 is further compressed to the effect of buffering, and the landing gear 320 is further downwards. Deeply insert the adjustment box 310, and when the desired angle is reached, release the handle, so that the chuck 314 snaps into the notch 324 corresponding to the current position under the action of the return spring 317, so that the backrest 200 is fixed. It is worth noting that turning the backrest 200 backwards will drive the lower ends of the landing gear 320 and the spring shaft 332 to swing, and the longer the length of the through holes 311a, 311b and the holes 312a, 312b along the swing direction, the more adjustable the backrest 200 will be. The greater the range of angles. Usually, the angle between the backrest 200 and the surface frame 110 is 90°-130°. When a larger angle range is needed, such as when used as a stretcher, the backrest 200 can be rotated forward to make the lower end of the landing gear 320 and the spring assembly 330 break away from the adjustment box 310, and then the backrest 200 can be bent backward to 180°. °.

When it needs to be folded, the backrest 200 is rotated forward first, so that the landing gear 320 and the spring assembly 330 are separated from the adjustment box 310 , and finally the backrest 200 is attached to the surface frame 110 . Then, the second side 113 of the surface frame 110 is lifted, and the movable frame 140 is separated from the surface frame 110 at this time, and the second foot frame 130 is approached to the first foot frame 120 under the action of gravity and finally fit together, the seat portion 100 The whole is flat. At this time, the first foot frame 120, the second foot frame 130, the movable frame 140, the backrest portion 200 and the surface frame are basically on the same plane, and the entire foldable seat is flat and can be stored in a small space.

For those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. A folding seat, comprising a seat, the seat is characterized in that it also includes: noodle rack; a first foot frame, the upper end of the first foot frame is hinged to the surface frame so as to be able to rotate relative to the surface frame at a hinged position; a movable frame hinged to the face frame so as to be rotatable relative to the face frame about the hinged position; a second tripod, the upper end of the second tripod is hinged to the free end of the movable frame, so as to be able to rotate relative to the movable frame with respect to the hinged position; The first pull rod, the two ends of which are respectively hinged to the first tripod and the movable frame, so that the movable frame and the first tripod are jointly rotated under the constraints of the surface frame and the first pull rod; The two ends of the second pull rod are respectively hinged to the seat part and the second foot frame, so that the second foot frame and the surface frame are jointly rotated under the constraints of the movable frame and the second pull rod. 2. The folding seat according to claim 1, characterized in that: The first stand includes a first support leg and a second support leg, the upper end of the first support leg is hinged to the first hinge position of the seat part, and the upper end of the second support leg is hinged to the second seat part of the seat part. hinge position; The movable frame includes a first movable rod and a second movable rod, the hinged end of the first movable rod is hinged to the third hinged position of the seat portion; the hinged end of the second movable rod is hinged to the seated portion The fourth hinged position; the straight line defined by the third hinged position and the fourth hinged position is substantially parallel to the straight line defined by the first hinged position and the second hinged position, the first movable rod and the second movable rod A third reinforcing rod is connected between them; the second tripod includes a third supporting leg and a fourth supporting leg, the upper end of the third supporting leg is hinged to the fifth hinged position of the first movable rod, the The upper end of the fourth support leg is hinged to the sixth hinged position of the second movable rod, and the line defined by the fifth hinged position and the sixth hinged position is substantially parallel to the third hinged position and the fourth hinged position. The straight line defined by the position; One end of the first pull rod is hinged to the seventh hinge position of the first movable rod, and the other end is hinged to the eighth hinge position of the first support leg; one end of the second pull rod is hinged to the first hinge position of the seating part. nine hinged positions, the other end being hinged to the tenth hinged position of said third support leg; The folding seat further includes a third pull rod and a fourth pull rod, one end of the third pull rod is hinged to the eleventh hinge position of the second movable rod, and the other end is hinged to the twelfth hinge position of the second support leg. position; one end of the fourth tie rod is hinged to the thirteenth hinge position of the seat part, and the other end is hinged to the fourteenth hinge position of the fourth support leg; the third tie rod is substantially parallel to the first The tie rods are substantially equal in length, and the fourth tie rod is substantially parallel to the second tie rod and has substantially the same length. 3. The folding seat according to claim 1, wherein the first stand includes a first support leg, a second support leg and a first reinforcing rod, and the two ends of the first reinforcing rod are respectively fixed to For the first support leg and the second support leg, the upper end of the first support leg is hinged to the first hinge position of the seat part, and the upper end of the second support leg is hinged to the second hinge position of the seat part; The movable frame includes a first movable rod and a second movable rod, the hinged end of the first movable rod is hinged to the third hinged position of the seat portion; the hinged end of the second movable rod is hinged to the seated portion The fourth hinged position; the straight line defined by the third hinged position and the fourth hinged position is substantially parallel to the straight line defined by the first hinged position and the second hinged position, the first movable rod and the second movable rod A third reinforcing rod is connected between them; the second tripod includes a third supporting leg, a fourth supporting leg and a second reinforcing rod, and the two ends of the second reinforcing rod are respectively fixed to the third supporting leg and the The fourth support leg, the upper end of the third support leg is hinged to the fifth hinge position of the first movable rod, the upper end of the fourth support leg is hinged to the sixth hinge position of the second movable rod, and A straight line defined by the fifth hinged position and the sixth hinged position is substantially parallel to a straight line defined by the third hinged position and the fourth hinged position; One end of the first pull rod is hinged to the seventh hinge position of the first movable rod, and the other end is hinged to the eighth hinge position of the first tripod; one end of the second pull rod is hinged to the first hinge position of the seating part. Nine hinge positions, the other end is hinged to the tenth hinge position of the second tripod. 4. The foldable seat according to claim 1, characterized in that, the foldable seat further comprises a backrest for leaning on, the bottom of the backrest is hinged to the seat so that the backrest can be positioned relative to the seat. The seat part rotates. 5. The foldable seat according to claim 4, characterized in that, the foldable seat further comprises a landing gear for adjusting the angle of the backrest relative to the seating part, the landing gear comprises a vertical part, the The upright portion is rotatably connected to the back portion such that the upright portion is rotatable relative to the back portion; The folding seat also includes an adjustment box, and the adjustment box is installed on the seating part; The free end of the vertical part of the undercarriage can be inserted into the adjustment box and fixed or released by the adjustment box, so that the rotation angle of the backrest relative to the seating part can be controlled. 6. The folding seat according to claim 5, characterized in that, the upper cover and the lower bottom of the adjustment box are respectively provided with landing gear through holes for the vertical part of the landing gear to pass through; The vertical part of the landing gear is provided with several notches, and a chuck is provided in the adjustment box for snapping into the notches to fix the position of the landing gear; The width of the landing gear through hole is slightly larger than the vertical part of the landing gear, and the length of the landing gear through hole is sufficient to allow the vertical part of the landing gear to swing due to the rotation of the backrest. 7. The folding seat according to claim 6, characterized in that, the folding seat further comprises a handle, one end of the handle is inserted into the adjustment box and fixedly connected with the chuck, and the other end extends out of the adjustment box outside. 8. The folding seat according to claim 5, characterized in that, the folding seat further comprises a spring assembly for relieving the impact force when the backrest adjusts the angle, the spring assembly includes a spring shaft and a main spring, the One end of the spring shaft is rotatably connected to the backrest and is basically parallel to the vertical portion of the landing gear, and the other end is a free end and can be inserted into the adjustment box; The main spring is sleeved on the outside of the spring shaft, and after the angle between the backrest and the seating part is greater than a preset angle, the two ends of the main spring are respectively adjusted by the backrest and the seat. box compression. 9 . The folding seat according to claim 6 , wherein a baffle protrudes vertically inward from the side of the undercarriage through hole of the upper cover of the adjustment box facing the notch, for Prevent the notch from being caught on the adjustment box. 10. The folding seat according to claim 6, wherein the adjustment box is equipped with a return spring, and one end of the return spring is fixedly connected to the chuck for restoring the chuck to the position where it is engaged with the notch. suitable location.